Weak wind effects in CNO driven winds of hot first stars

摘要

Context. During the evolution of rotating first stars, whichinitially consisted of only hydrogen and helium, CNO elements mayemerge to their surface. These stars may therefore have winds that aredriven only by CNO elements. Aims. We study weak wind effects (Gayley-Owocki heating andmulticomponent effects) in stellar winds of first generation starsdriven purely by CNO elements. Methods. We apply our NLTE multicomponent models and hydrodynamical simulations. Results. The multicomponent effects (frictional heating anddecoupling) are important particularly for low metallicity winds, butthey influence mass loss rate only if they cause decoupling forvelocities lower than the escape velocity. The multicomponent effectsalso modify the feedback from first stars. As a result of thedecoupling of radiatively accelerated metals from hydrogen and helium,the first low-energy cosmic ray particles are generated. We study theinteraction of these particles with the interstellar medium concludingthat these particles easily penetrate the interstellar medium of agiven minihalo. We discuss the charging of the first stars by means oftheir winds. Conclusions. Gayley-Owocki heating, frictional heating, and thedecoupling of wind components occur in the winds of evolvedlow-metallicity stars and the solar metallicity main-sequence stars. Key words: stars: winds, outflows - stars: mass-loss - stars: early-type - hydrodynamics